Posted
by
timothy
on Monday July 20, 2009 @01:40PM
from the this-is-awesome dept.

Mike writes "Earthquake news abounds as of late — recently a team of researchers from five universities unveiled an seven-story earthquake-proof wooden building that is capable of withstanding severe earthquakes. Featuring a structurally efficient nail distribution and a 63 anchor tie down system, the wooden condominium survived a test using an E-Defense shake table, which simulated a 7.5 magnitude quake (check out the video!)"

The question is- does it last in such a way that you just keep living like nothing happened after the quake? or.. lasts, as in, doesn't kill everybody in and around the building, but you probably want a new one if it goes through an earthquake even once..

Believe it or not current structural code functions to provide surviveability for it's occupants. I'm an architect in southern california and prior to 1997 buildings were designed to basically allow occupants to escape, however due to the financial toll of northridge the structural code was revamped to prevent flexing which would result in the building not having sever cosmetic damage. This however resulted in drastically increased construction costs. The fact is you want a building that will flex as opposed to break. It always cracks me up because there is a war between wood mfgs and steel mfgs. Currently your typical stick framed building stops at three stories (in southern california) after this you need to switch to steel or concrete. Manufactureres like simpson strong tie are working hard to push the limit of wood to allow them a greater market share.

The general idea is to have the building _not_ collapse on top of you.

As a lifetime resident of Los Angeles that's experienced all of the big quakes back to the 1970's, I've been in stick construction houses for all of the quakes and didn't even experience a broken window. They shake like crazy and it's loud as hell in the big ones, but the stick design is very flexible.

The older homes here 1930's have foundation problems more than anything else in the big ones. They tend to be lathe/plaster walls, but

From watching the movie, it remained in one piece, with no visible change. Maybe there was structural damage, but the article didn't mention it. It looked like it was shaking a bit, so if it'd had sheetrock, the sheetrock might have become cracked. If there were books on shelves, the books likely would have fallen off.

Also, check out the movie, if you've ever lived through an earthquake, it looks just like a real one feels, not sharp shaking back and forth, but gentle moving in seeming random direction

I built this lighthouse in the swamp. People said I was daft to build a lighthouse in a swamp, but I built it all the same, just to show 'em.

It sank into the swamp.

So I built another one. That one sank into the swamp. So I built a third lighthouse. That one burned down, fell over, and then sank into the swamp. But the fourth one stayed up! And that's what you're gonna get, lad, the strongest lighthouse in this swamp.

This may sound facetious, but I had a similar question the first time I saw a large Sodium-sulfide (NaS) battery. It was the size of a garden shed, and basically was filled with molten sodium. The engineers said that it was safe from thunderstorms, tornadoes, tree falls, and earthquakes. My first question was "it is safe from two or three of those if they happen at the same time?"

A now very pale engineer answered "no". I guess they hadn't considered a tree falling on it in the rain, and we all know h

I suppose you make sure your table salt doesn't get wet either, eh? It's got the same chemical structure and behaves similarly to sodiumsulfide because they are both salts. Wet NaS is no more going to have a violent chemical reaction with water than NaCl (aka table salt) will.

Now, what might be a danger would be the incredibly massive transfer of thermal energy from the molten NaS to water, probably creating a super-heated steam almost instantly. I could see the area around a NaS battery becoming quite d

Let's say that you and your MOTAS are having a romantic candlelight dinner when the earthquake hits. All it takes is one of the candles falling on the right spot and you've got an earthquake-caused fire even if it's an all-electric home. Or, if you prefer, you're making fish and chips and the quake spills the grease from the fryer onto a hot burner. There are lots of ways to start a fire during an earthquake even if the gas (if you have it) tur

It doesn't make a difference, does it? I mean : your standard steel or concrete house will burn as well as a wooden one, unless it's completely empty of any inflammable materials (and even then, I'm not sure it would be structurally okay once the flames are out).

I'm living in a wooden house (although it's only 2 stories high), and we had an approximately 1minute long 7.4 earthquake slightly over a year ago (just two months after being visited by a hurricane actually). From what my sister in law who was in i

"Flammable" is a silly word (although I'm sure it's crept into dictionaries by now). "Inflammable" means "likely to burst into flame". Because this confused the illiterate, people wisely started using "flammable" on warning signs, and now it's as common as "ain't". "Inflammable" remains the better word.

"Inflammable" means "likely to burst into flame". Because this confused the illiterate

Confused the illiterate? Literally one meaning of the prefix "in-" is not [onelook.com] as in "insane", not sane. Or "inseparable", not separable. Following the rule "inflammable" would mean "not flammable", so "flammable" is the better word for easy to burn. What is confusing is changing the rules.

But then again, English is a Crazy Language [amazon.com]. In what other language does feet smell and noses run. Or look at the plural of tooth, "te

"inflammable" means that the substance in question can inflame. "inflame" is the verb which means "to begin to burn". It is *exactly* the same verb that's the source of the word "inflammation", which in medical terms refers to the heat that's given off by the extra blood flow to the affected area.

It's not a question of "in" being a prefix. In this word it's not a prefix. It's part of the root of the word.

in-flamable is just the english word every native english speaker should use for "not flamable", your logic only makes sense if you are not an native english speaker.

"in" is not only a synonym for "not" but also an emphasizing prefix. All over europe (and that is where modern english has its origin from):spanish: inflameable -> inflamable, german: in-flame-able -> ent-flamm-bar, italian: inflameable -> accendibile / in-fiamm-abile.

I don't recall the "in-" prefix means "lots" so I checked my dictionaries, I have 4, as well as OneLook [onelook.com]. With OneLook I checked the first 10 links to the definition and not one gave "lots" as a definition. Now "in" as in into and "towards" was given as well as other definitions [wiktionary.org] but not "lots". Can you give an example of it used that way?

The "in-" prefix is used as an intensifier ("towards" for verbs, but the stronger "has" or even "has lots" for adjectives). Each of the examples I gave above were different places along that spectrum. Ingenious as "has the generative nature", infamous as "overly famous" or "ill-famed" but not "non-famous". Incorporate as "create body" (but incorporeal as "without body"). "Inform" as "create form" (but also "without form" in older usage, amusingly). Even my accidental example, "intense" as "has lots of

Generally speaking, a properly impregnated wooden house will last longer than a concrete one. An even the ones which were not impregnated will still have the large beam structure standing after burning down. That is because the outer wood burns, becomes coal and does not let enough oxygen to the wood so it can continue to burn.

This is actually very old news. I live in Earthquake city, USA, so most houses here are wooden, so they can twist (and businesses are usually in buildings set on rollers). I talked to a guy from Israel, asking what the buildings were like there (If they had a more US or European way to decorating an interior) and he said "Well, first, there's no wood. It's concrete. We're not afraid of earthquakes hitting our houses, we're afraid of rockets hitting them."

Am I the only one that didn't find that earthquake video very impressive? I would hope any building would survive that. Looks like a very tame earthquake.

Also it was really light... no siding, no SHINGLES, no furniture, probably no plumbing. NOT impressed.

It does look weak, but I have participated in quake testing and real earthquakes. You can really feel the motion on the roof. And that "unimpressive motion" is pretty dramatic when you are in the 4th floor of building and you have to sit there and wait to see what happens while everything gets shaken off your desk and wall.

But I agree that siding and shingles might change the loading a bit. But remember, this is research. They are just proving a concept.

Also it was really light... no siding, no SHINGLES, no furniture, probably no plumbing. NOT impressed.

Yeah, they could have made it much cooler with computer generated graphics, instead they probably blew their whole production budget on the world's largest shake table, a million pounds of wood, and a huge team of highly trained Japanese scientists and engineers. If nothing else, it needs more fire, and way more Godzilla. Two thumbs down!

So a magnitude 7.5 [wikipedia.org] sounds like a tame earthquake to you? And you figure it should be simple to make a wood building that survives such an earthquake, especially without siding or furniture?

Watch the video from inside the building. The earthquake doesn't look that impressive in the outside video because of the scale, and our lack of our ability to sense that properly. However, after viewing the inside video, I can say there's no way I'd want to go through that kind of quake.

Thanks, someone had posted a link above. While the outside video doesn't look like much, maybe because of scale, the one inside does.

What I find real amazing is that a big enough table was made that was capable of having a building that big built on it then have the table shaken like that. It reminds me of the aircraft catapults [wikipedia.org] on carriers.

the whole purpose of something like this is to justify wood as a acceptable material for 3 or more stories (well in california) by doing this they increase the market share of wood. See simpson strong tie.... truth is this was an empty home with no realistic live loads. ie file cabinets couches TV etc. You also have to add dead loads like windows, doors finishes etc.

Simulations are nice and all, but it's a bit inaccurate to say it "survived a 7.5 magnitude quake" when it didn't actually.

You're just arguing semantics. The forces applied by these shake tables are close enough to the real thing to give us a good idea of what the building can survive. Yes, you can argue "it's not a real quake," but that's pointless. Are they supposed to wait for a real quake for their test?

Also, adding in 63 steel rods seems to defeat the purpose of calling it a "wooden building".

As others have said, they're just trying to provide evidence that wood is a viable building material for larger buildings.

Nowhere does anybody say that wood has to be the only material used. It doesn't have to be all one thing or the other. Also, it appears from the unfortunately sparse article that the steel only helps to keep the building from rocking excessively. It doesn't support the weight. A building like this would likely be a good bit cheaper than a similar steel building.

Will anything be built like this? Maybe not, but it's interesting anyway.

I read an article along this line earlier this year. Wooden buildings have a better survival rate on the Indian subcontinent, in India and Pakistan than stone buildings. Whereas wood ones can last centuries stone ones don't last as long.

Technically the bottom floor which isn't enclosed counts as a story, it would be the basement actually.However, that part looks like it is made up of steel beams, not wood. Although it looks like a lot of the joints and supports are metal as well. So they are still lying!

I don't know what they are trying to prove with this crap here but I am not at all impressed by that video -- I mean the building is completely empty and naked! Wouldn't the siding, roofing, walls, doors, windows, people, and furnishings make the building more heavy (and more likely to collapse)? Wouldn't the plumbing make the building more rigid and again, more likely to collapse? If I am incorrect please let me know, but it seems to me that this experiment proves precisely nothing.

Please. How much exactly do you think is known about keeping buildings together in an earthquake? The body of knowledge is improving, but there is still a lot we don't know. These guys have developed a way that will keep buildings together better than what we had previously. Even if no one ever actually builds a seven story condo, this is knowledge that will help in any kind of wood construction.

Besides, if you are not impressed then you missed the coolest part of the video. They have a platform there that can move a million pound structure around in simulation of a real earthquake. If that's not cool technology, I don't know what is.

It would be interesting to see how a traditionally constructed wooden building fares in that test. If, built out to the same level, a traditional structure collapses like it's made of toothpicks, then this proves something quite significant.

No, things like siding would just have to be torn off, to make sure the inside structure was still sound. You don't want to cover up the core structure for cosmetic reasons.. Also, that stuff does not really add much weight, and would be more likely to suffer damage, (ie, windows cracking, siding torn, Kitchen cabinets damaged, etc) that would not damage the integrity of the building, IE, they don't care if they have to replace the windows, the key is that the building doesn't collapse.

Actually the building had steel plates on each floor to represent the real weight of the finishing materials and furnishings. There were a few dummy rooms with furnishing etc. Earthquakes don't look that bad from a distance. The shaking is strong though and the building has to stand up to it. Some of the forces exerted are stronger than gravity (the Northridge quake apparently exceeded 1.0 g -- up to 1.8 I think). In this case they are testing a new construction design and want to see if the real buildi

I don't know what they are trying to prove with this crap here but I am not at all impressed by that video -- I mean the building is completely empty and naked! Wouldn't the siding, roofing, walls, doors, windows, people, and furnishings make the building more heavy (and more likely to collapse)? Wouldn't the plumbing make the building more rigid and again, more likely to collapse?

Not plumbing. Neither copper nor plastic (and I doubt they'll be using cast iron in new construction) has enough rigidity to make the building more rigid, particularly since it isn't even tied into the structure (it's just on sheet-metal hangars, unless that's different in earthquake areas).

Good for them, but it doesn't really surprise me that you can make a building of that type/size earthquake-resistant. While the building is technically "wood", they are using a lot of engineered lumber (lumber that is made from particles/chips of wood held together with a binder). Looking at the pictures in the article, the building is sheathed in OSB (oriented strand board), which acts as a very good shear panel. The floors are supported using TJIs (Truss Joist I-Beams), where the top and bottom of the TJI is made of laminated wood and OSB is used as the webbing of the truss. These things are very strong, and they are anchored on the ends with galvanized steel hangars, which are very secure. The weak point in wood structures is frequently in how the pieces are joined together, and the hangars largely address that. Engineered lumber is increasingly popular in US wood construction, not for earthquake reasons, but because it is very consistent - it comes in the exact size you order, doesn't warp/twist/bow, etc., and it doesn't have knotholes. Where this building uses regular milled lumber they often stack it 6-7 deep to make columns.

They are still using steel - in the foundation and in the tiedown system, to do critical structural work. Nothing wrong with that, it's the smart thing to do. Steel has awesome tensile strength.

My guess is that a mid-rise made using this method would be significantly cheaper than reinforced concrete, and somewhat cheaper than steel. The difference is that a steel framed building will be put together by skilled welders, while the framers putting this building up will tend to be of a lower skill level - one reason this building would be cheaper - and you'll have to keep a closer eye on the construction. Given the need for engineered lumber, selective use of steel, and close attention to how the building is put together, I don't see this as a panacea for earthquake-resistant housing in the third-world. I'm sure they would love it in California, though. The big challenge is ensuring consistent construction and getting the changes in the building code (particularly in CA, which is more earthquake conscious than other states). Beyond that, it's just a question of cost.

If I remember correctly, pagoda temples built in Japan are famous for their earthquake-proof designs because the design of the pagoda itself and the use of hardwood structural members meant the building would absorb the shock of an earthquake, which meant the building could even survive the occasional very strong earthquake that are common in Japan.

Indeed, the Taipei 101 skyscraper uses the same structural principle found in Japanese pagodas in order to withstand the earthquakes that happen on the island of

There's no technical problem making a wood building that strong. It's the enforcement that's the problem. Wood has good tensile strength, but the joints usually used in wood construction don't.

A few years ago, after some hurricanes, many Florida builders were discovered not to be building to code. Hurricane-proofing for small wood structures mostly consists of putting in metal brackets at joints to give wood-to-wood joints tensile strength. Not only do the brackets have to be put in, nails have to be hammered into all the holes in the brackets. Many contractors were sloppy about that, resulting in a big loss of tensile strength and major damage (like roofs ripped off) during hurricanes.

A big problem in the Third World is bad concrete mixes. Much concrete construction goes up without enough cement in the mix, and that results in building collapses.

Here's a good project for someone - develop a low-cost hand held device for concrete testing. [state.il.us] The existing techniques are slow, labor-intensive, and a pain to use. Tests for hardened concrete
usually involve cutting out a plug and sending it to a lab elsewhere. Small portable devices would be a big help here.

Same here. I don't know if I've ever been in an earthquake but I've been in severe thunderstorms and had close encounters with hurricanes. Growing up in Florida friends of mine and I had this saying, it was easy to tell a true Floridian from a transplant, when a hurricane comes along the Floridian says it's tyme to batten the hatches whereas the transplant panics, throws up his arms in the air, and screams "Let's get out of here."

Not as big a problem as it might seem. As pointed out upthread [slashdot.org], the structure was constructed with a lot of engineered lumber. The binders in the engineered lumber probably have some inherent insect & mold deterrent properties, which could be bolstered by the addition of insecticide and/or fungicide.